$NetBSD: patch-aj,v 1.3 2014/09/25 10:58:02 jperkin Exp $

Support strerror().

--- rw/libpnmrw.c.orig	1996-06-25 08:50:42.000000000 +0000
+++ rw/libpnmrw.c
@@ -32,6 +32,7 @@
 /* #define MSDOS */
 #endif
 
+#include <errno.h>
 #include <stdio.h>
 #include "libpnmrw.h"
 
@@ -128,15 +129,13 @@ pm_freearray(char **its, int rows)
 static void
 pm_perror(char *reason)
 {
-#if defined(BSD4_4)
-    __const extern char *__const sys_errlist[];
-#else
-    extern char *sys_errlist[];
-#endif
-    extern int errno;
     char *e;
 
+#if defined(__STDC__) && !defined(MISSING_STRERROR)
+    e = strerror(errno);
+#else
     e = sys_errlist[errno];
+#endif
 
     if (reason != 0 && reason[0] != '\0')
 	fprintf(stderr, "%s: %s - %s\n", progname, reason, e);